Particulate water absorbing agent
The purpose of the present invention is to provide a particulate water absorbing agent having both a high water absorption multiplying factor and a high water absorption rate and a method for manufacturing the same. The present invention is a particulate water absorbing agent for which CRC is 30 to 50 g/g, wherein the weight average particulate diameter (D50) is 200-600 μm, and the DRC index given by the following formula is a specific value (for example, 43, 30, or 20) or less: DRC index=(49−DRC5min [g/g])/(D50 [μm]/1000).
1. A particulate water absorbent agent with a centrifuge retention capacity (CRC) of 30 to 50 g/g, wherein
a weight average particle diameter (D50) is 200 to 600 μm, and
an index of DRC represented by the following equation is 43 or less:
Index of DRC=(49−DRC5min [g/g])/( D 50 [μm]/1000).
2. The particulate water absorbent agent of claim 1 , wherein the index of DRC is 30 or less.
3. The particulate water absorbent agent of claim 1 , wherein the index of DRC is 20 or less.
4. The particulate water absorbent agent of claim 1 , wherein a saline flow conductivity (SFC) is 0 to less than 30(×10 −7 ·cm 3 ·s·g −1 ).
5. The particulate water absorbent agent of claim 1 , wherein surface tension is 66 mN/m or greater.
6. The particulate water absorbent agent of claim 1 , wherein a particle shape is an irregular pulverized shape.
7. The particulate water absorbent agent of claim 1 , wherein a moisture absorption fluidity (B. R.) is 50% by weight or less.
8. The particulate water absorbent agent of claim 1 , wherein a water soluble component (Ext) is 25% by weight of less.
9. The particulate water absorbent agent of claim 1 , wherein a degradable soluble component is 30% by weight of less.
10. The particulate water absorbent agent of claim 1 , wherein an absorption against pressure (AAP) is 18 g/g or greater.
11. The particulate water absorbent agent of claim 1 , wherein an absorption against pressure (AAP) is 26 g/g or greater.
12. The particulate water absorbent agent of claim 1 , wherein an internal gas bubbles ratio defined by the following equation is 0.5 to 2.5%:
(internal gas bubbles ratio [%])={(true density [g/cm 3 ])−(apparent density [g/cm 3 ])}/(true density [g/cm 3 ])×100.
13. The particulate water absorbent agent of claim 1 , wherein a bulk specific gravity is 0.57 to 0.75.
14. The particulate water absorbent agent of claim 1 , wherein a diffusing absorbency under pressure 60 minutes is 18 g/g or greater.
15. The particulate water absorbent agent of claim 1 , wherein a diffusing absorbency under pressure 10 minutes is 7 g/g or greater.
16. The particulate water absorbent agent of claim 1 , having a polyacrylic acid (salt)-based water absorbent resin as a main component.
17. The particulate water absorbent agent of claim 1 , further comprising at least one moisture absorption fluidity improving agent selected from the group consisting of multi-component metal compounds comprising a divalent metal cation and a trivalent metal cation having a hydrotalcite structure and a hydroxyl group, and water insoluble metal phosphate consisting of a phosphoric acid anion and a divalent or trivalent metal cation.
18. An absorbent core comprising the particulate water absorbent agent of claim 1 .
19. A sanitation article comprising the absorbent core of claim 18 .